title: Isolation and analysis of bacteria with antimicrobial activities from the marine sponge Haliclona simulans collected from Irish waters.
abstract: Samples of the marine sponge Haliclona simulans were collected from Irish coastal waters, and bacteria were isolated from these samples. Phylogenetic analyses of the cultured isolates showed that four different bacterial phyla were represented; Bacteriodetes, Actinobacteria, Proteobacteria, and Firmicutes. The sponge bacterial isolates were assayed for the production of antimicrobial substances, and biological activities against Gram-positive and Gram-negative bacteria and fungi were demonstrated, with 50% of isolates showing antimicrobial activity against at least one of the test strains. Further testing showed that the antimicrobial activities extended to the important pathogens Pseudomonas aeruginosa, Clostridium difficile, multi-drug-resistant Staphylococcus aureus, and pathogenic yeast strains. The Actinomycetes were numerically the most abundant producers of antimicrobial activities, although activities were also noted from Bacilli and Pseudovibrio isolates. Surveys for the presence of potential antibiotic encoding polyketide synthase and nonribosomal peptide synthetase genes also revealed that genes for the biosynthesis of these secondary metabolites were present in most bacterial phyla but were particularly prevalent among the Actinobacteria and Proteobacteria. This study demonstrates that the culturable fraction of bacteria from the sponge H. simulans is diverse and appears to possess much potential as a source for the discovery of new medically relevant biological active agents.
authors.affiliation: Environmental Research Institute, University College Cork, Cork, Ireland.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Kennedy
authors.forename: Paul
authors.initials: P
authors.lastname: Baker
authors.forename: Clare
authors.initials: C
authors.lastname: Piper
authors.forename: Paul D
authors.initials: PD
authors.lastname: Cotter
authors.forename: Marcella
authors.initials: M
authors.lastname: Walsh
authors.forename: Marlies J
authors.initials: MJ
authors.lastname: Mooij
authors.forename: Marie B
authors.initials: MB
authors.lastname: Bourke
authors.forename: Mary C
authors.initials: MC
authors.lastname: Rea
authors.forename: Paula M
authors.initials: PM
authors.lastname: O'Connor
authors.forename: R Paul
authors.initials: RP
authors.lastname: Ross
authors.forename: Colin
authors.initials: C
authors.lastname: Hill
authors.forename: Fergal
authors.initials: F
authors.lastname: O'Gara
authors.forename: Julian R
authors.initials: JR
authors.lastname: Marchesi
authors.forename: Alan D W
authors.initials: AD
authors.lastname: Dobson
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000378:metabolism; D000898:Antibiosis / Q000235:genetics*; D001419:Bacteria / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D016000:Cluster Analysis; D007494:Ireland; D008969:Molecular Sequence Data; D010453:Peptide Synthases / Q000235:genetics; D010802:Phylogeny; D048630:Polyketide Synthases / Q000235:genetics; D011161:Porifera / Q000235:genetics / Q000382:microbiology*; D012336:RNA, Ribosomal, 16S; D017422:Sequence Analysis, DNA; D013045:Species Specificity
chemical_list: D000890:Anti-Infective Agents; D012336:RNA, Ribosomal, 16S; D048630:Polyketide Synthases; D010453:Peptide Synthases